<template>
    <div>
        <div class="header-abs" v-show="showAbs" @click="go">
          <em class="iconfont left1 arrow-left-bold">&#xe6e8;</em>
        </div>
        <div class="header-fixed" v-show="!showAbs" :style="opacityStyle">
          <div class="left2">
              <div class="iconfont  arrow-left-bold">&#xe6e8;</div>
          </div>
          <p>景点详情</p>
        </div>     
    </div>
</template>

<script>
export default {
  data() {
    return {
      showAbs: true,
      opacityStyle: {
        opacity: 0
      }
    };
  },
  methods: {
    go() {
      this.$router.go(-1);
    },
    handleScroll() {
      //document.documentElement.scrollTop   pc端使用  document.body.scrollTop 移动端使用
      console.log(document.documentElement.scrollTop);
      const top = document.documentElement.scrollTop;
      if (top > 60) {
        let opacity = top / 140;
        opacity = opacity > 1 ? 1 : opacity;
        this.opacityStyle = { opacity };
        this.showAbs = false;
      } else {
        this.showAbs = true;
      }
    },
    
  },
  activated() {
    console.log('ddddd');
      window.addEventListener("scroll", this.handleScroll);
    },
    deactivated() {
      //页面即将替换新的页面的时候
      window.removeEventListener("scroll", this.handleScroll);
    }
};
</script>

<style lang="scss" scoped>
.header-abs {
  position: absolute;
  left: 0.2rem;
  top: 0.2rem;
  width: 0.8rem;
  height: 0.8rem;
  line-height: 0.8rem;
  border-radius: 0.4rem;
  text-align: center;
  background: rgba(0, 0, 0, 0.8);

  z-index: 999;
  .left1 {
    color: #fff;
    font-size: 0.4rem;
  }
  
}
.header-fixed {
  z-index: 2;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 0.86rem;
  line-height: 0.86rem;
  text-align: center;
  color: #fff;
  background: #00bcd4;
  font-size: 0.32rem;
  .left2{
    width: .5rem;
    float: left;
  }
  p{
    text-align: center;
  }
  .header-fixed-back {
    position: absolute;
    top: 0;
    left: 0;
    width: 0.64rem;
    text-align: center;
    font-size: 0.4rem;
    color: #fff;
  }
}
</style>